path: root/include/linux/device.h

/*
 * device.h - generic, centralized driver model
 *
 * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
 * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2008-2009 Novell Inc.
 *
 * This file is released under the GPLv2
 *
 * See Documentation/driver-model/ for more information.
 */

#ifndef _DEVICE_H_
#define _DEVICE_H_

#include <linux/ioport.h>
#include <linux/kobject.h>
#include <linux/klist.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/atomic.h>
#include <asm/device.h>

struct device;
struct device_private;
struct device_driver;
struct driver_private;
struct module;
struct class;
struct subsys_private;
struct bus_type;
struct device_node;
struct iommu_ops;

struct bus_attribute {
	struct attribute	attr;
	ssize_t (*show)(struct bus_type *bus, char *buf);
	ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
};

#define BUS_ATTR(_name, _mode, _show, _store)	\
struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)

extern int __must_check bus_create_file(struct bus_type *,
					struct bus_attribute *);
extern void bus_remove_file(struct bus_type *, struct bus_attribute *);

/**
 * struct bus_type - The bus type of the device
 *
 * @name:	The name of the bus.
 * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
 * @dev_root:	Default device to use as the parent.
 * @bus_attrs:	Default attributes of the bus.
 * @dev_attrs:	Default attributes of the devices on the bus.
 * @drv_attrs:	Default attributes of the device drivers on the bus.
 * @match:	Called, perhaps multiple times, whenever a new device or driver
 *		is added for this bus. It should return a nonzero value if the
 *		given device can be handled by the given driver.
 * @uevent:	Called when a device is added, removed, or a few other things
 *		that generate uevents to add the environment variables.
 * @probe:	Called when a new device or driver add to this bus, and callback
 *		the specific driver's probe to initial the matched device.
 * @remove:	Called when a device removed from this bus.
 * @shutdown:	Called at shut-down time to quiesce the device.
 * @suspend:	Called when a device on this bus wants to go to sleep mode.
 * @resume:	Called to bring a device on this bus out of sleep mode.
 * @pm:		Power management operations of this bus, callback the specific
 *		device driver's pm-ops.
 * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
 *              driver implementations to a bus and allow the driver to do
 *              bus-specific setup
 * @p:		The private data of the driver core, only the driver core can
 *		touch this.
 *
 * A bus is a channel between the processor and one or more devices. For the
 * purposes of the device model, all devices are connected via a bus, even if
 * it is an internal, virtual, "platform" bus. Buses can plug into each other.
 * A USB controller is usually a PCI device, for example. The device model
 * represents the actual connections between buses and the devices they control.
 * A bus is represented by the bus_type structure. It contains the name, the
 * default attributes, the bus' methods, PM operations, and the driver core's
 * private data.
 */
struct bus_type {
	const char		*name;
	const char		*dev_name;
	struct device		*dev_root;
	struct bus_attribute	*bus_attrs;
	struct device_attribute	*dev_attrs;
	struct driver_attribute	*drv_attrs;

	int (*match)(struct device *dev, struct device_driver *drv);
	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
	int (*probe)(struct device *dev);
	int (*remove)(struct device *dev);
	void (*shutdown)(struct device *dev);

	int (*suspend)(struct device *dev, pm_message_t state);
	int (*resume)(struct device *dev);

	const struct dev_pm_ops *pm;

	struct iommu_ops *iommu_ops;

	struct subsys_private *p;
};

/* This is a #define to keep the compiler from merging different
 * instances of the __key variable */
#define bus_register(subsys)			\
({						\
	static struct lock_class_key __key;	\
	__bus_register(subsys, &__key);	\
})
extern int __must_check __bus_register(struct bus_type *bus,
				       struct lock_class_key *key);
extern void bus_unregister(struct bus_type *bus);

extern int __must_check bus_rescan_devices(struct bus_type *bus);

/* iterator helpers for buses */
struct subsys_dev_iter {
	struct klist_iter		ki;
	const struct device_type	*type;
};
void subsys_dev_iter_init(struct subsys_dev_iter *iter,
			 struct bus_type *subsys,
			 struct device *start,
			 const struct device_type *type);
struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
void subsys_dev_iter_exit(struct subsys_dev_iter *iter);

int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
		     int (*fn)(struct device *dev, void *data));
struct device *bus_find_device(struct bus_type *bus, struct device *start,
			       void *data,
			       int (*match)(struct device *dev, void *data));
struct device *bus_find_device_by_name(struct bus_type *bus,
				       struct device *start,
				       const char *name);
struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
					struct device *hint);
int